The present invention relates to a replaceable signal cable for connection of a specific type of cellular phone to a sound controlled or externally dialed hand-free system. It enables the hand-free system to be adapted for universal use on all types of cellular phones by simple selection of a proper signal cable in use. In other words, it relates more particularly to a signal cable for a hand-free system, which can be selectively replaced with ease so as to make all types of cellular phones universally adapted to one single hand-free system. The signal cable is equipped with a first connecting plug coupled with a cellular phone and a second connecting plug connected to a hand-free system. A dial-decoding IC or circuitry housed in either the first connecting plug for a cellular phone or the second connecting plug for a hand-free system is adopted according to codes set by a standard communication protocol for each type of cellular phone. So, simple replacement of a signal cable permits a hand-free system to be universally applicable to all kinds of cellular phones.
Usually a signal cable is adapted for use between a sound-controlled or externally dialed hand-free system and a particular type of cellular phone operated on codes defined by a specific communication protocol for cellular phones. To make a sound-controlled or externally dialed hand-free system compatible with a cellular phone, communication codes transmitted from the cellular phone must be decoded with success by the hand-free system. To permit a sound-controlled or externally dialed hand-free system to be universally adapted for all types of cellular phones operated on different code protocols, a replaceable signal cable which is adapted for one specific type of cellular phone is developed. Such a signal cable must be selectively substituted with ease so as to make a sound-controlled or externally dialed hand-free system universally compatible with all types of cellular phones.
Cellular phones have been widely used by people all over the world, and in modern big cities, a very high percentage of people carry a cellular phone all around. Multiple types of cellular phones provided with various functions have been marketed at an astounding speed, and their related peripheral equipment is also developed at the same pace and sold on markets everywhere. Hand-free system for use in a vehicle is the hottest commercial item in recent years. It is widely accepted by consumers as a result of consideration of driving safety and convenience of use in practical operation of a cellular phone in a moving vehicle. The phenomena is described in a term of xe2x80x9ccommunication on movexe2x80x9d by people. This hand-free system is not ideal enough to make driving that safe when operating a cellular phone in spite of its facility brought to drivers. There are still hidden hazards in driving when using a cellular phone, especially dialing a cellular phone in driving. To solve such a problem, a sound-controlled dial system or a dial keyboard mounted to a steering wheel for dialing purpose is developed. However, the conventional sound-controlled or externally dialed hand-free system has the following disadvantages in practical use.
1. Different types of cellular phones, or cellular phones produced by various makers adopt codes defined by different communication protocols, i.e., the dialing codes associated with the dial keyboards for 0, 1, 2, . . . 9, SEND, END and etc. are varied from one cellular phone to another. So, makers must produce one particular sound-controlled or externally dialed hand-free system for each type of cellular phone individually. This makes production cost high and stock house full of various kinds of hand-free systems.
2. One family may have more than one cellular phone among its members, more than one type of hand-free systems must be purchased. When a cellular phone is traded for a new one, a new hand-free system must be set again, thus making unnecessary waste of money.
3. Vehicles designed with the idea of xe2x80x9ccommunication on movexe2x80x9d, a hand-free system is inevitably installed in the vehicles as a standard facility and operates in combination with a vehicle""s audio stereo system. So, if the problem of compatibility of a hand-free system with a cellular phone can not be tackled, i.e., a driver""s cellular phone is not compatible with a vehicle""s hand-free system, he or she is not able to benefit from the convenience of such an equipment.
The inventor noticing this disadvantage of a conventional sound-controlled or externally dialed hand-free system came up with a signal cable having a dial-decoding IC or circuitry integrally housed therein for each individual cellular phone in combination with a sound-controlled or externally dialed hand-free system. Thereby simple replacement of signal cables permits the sound-controlled or externally dialed hand-free system to be universally adapted for all types of cellular phones.
Therefore, the primary object of the present invention is to provide an replaceable signal cable each having a specific dial-decoding IC or circuitry integrally housed therein, in combination with a sound-controlled or externally dialed hand-free system. Each signal cable is adapted for each type of cellular phone whereby simple selection of a proper signal cable for each type of cellular phone which is operated on codes set according to different international communication protocols for cellular phones. Thus, making a hand-free system universally adapted for all types of cellular phones becomes possible.